Electric lamp base end structure



June 11, 1963 R. J AYRES ELECTRIC LAMP BASE END STRUCTURE Filed Feb. 1,1961 Inveen tov: Re cginabd J. Agves b3 5mm is A o w neg United StatesPatent 3,093,768 ELECTRIC LAMP BASE END STRUCTURE Reginald J. Ayres,Shaker Heights, Ohio, assignor to General Electric Company, acorporation of New York Filed Feb. 1, 1961, Ser. No. 86,391 4 Claims.(Cl. 313318) This invention relates to electrical devices such asincandescent lamps and gaseous discharge devices, and more particularlyto a base end construction for such devices.

Double-ended miniature incandescent lamps of the type having terminalcontact means or a base structure at each end are in general use atpresent for various applications, such as automotive dome and dashlighting and tail lamps. Such double-ended lamps are adapted for usewith simple spring-clip type sockets similar to those commonly used forcartridge fuses, for example.

One form of such double-ended miniature type incandescent lamp is of theso-called baseless type disclosed and claimed in co-pending UnitedStates application Serial No. 848,282, Ayres et al., filed October 23,1959 and assigned to the assignee of the present invention. The baselesslamp therein disclosed comprises an elongated glass bulb or envelopeprovided at its opposite ends with protruding glass stem press portionsthrough which the lead-in wires of the lamp are sealed. The lead-inwires are bent around the ends of the lamp stem press portions to extendback along one of the flat sides of the respective stem press to therebyserve as the terminal contacts for the lamp. For certain applications,however, it may be desirable to provide such type lamps with metal endcaps or bases at their opposite ends to serve as the terminal contactsfor the lamp.

It is an object of my invention, therefore, to provide a simple andinexpensive base end structure for electric lamps or similar devices ofthe type having protruding stern press portions through which are sealedthe lead-in conductors of the lamp.

Another object of my invention is to provide a doubleended electric lampor similar device of the type having protruding flat glass stem pressportions at its opposite ends and having metal end caps or basestructures which can be quickly and easily assembled in place on thestem lead-in conductors thereof.

Briefly stated, in accordance with one aspect of the invention, a lampof the type having a protruding glass stern press portion through whichone of the lamp lead-in wires is sealed, is provided with a shallowindentation in one or both of the flat sides of the stem press, eachindentation forming a sharp lateral shoulder on the stem press facinginwardly of the envelope. The lead-in wire is bent around the outer endof the stem press to extend back alongside one of the flat sides thereofand across the indentation therein. A hollow base member or metal endcap, having flat sides corresponding to the flat sides of the stem pressand provided with an inward spring tongue or detent in one or both ofits flat sides, is slipfitted over the end of the stern press and pushedback until the spring tongue or tongues snap into the respectiveindentation in the stem press so as to cause their free ends to becaught behind the lateral shoulder or shoulders on the stern press,thereby locking the base securely in place on the stem press againstendwise removal therefrom. During this assembly of the base onto thestem press of the lamp, the spring action of the spring tongueautomatically acts to deform and resiliently clamp the lead-in wirefirmly against the bottom of the respective indentation in the stempress to thereby form a good electrical connection with the lead-inwire.

Patented June 11, 1963 Further objects and advantages of my inventionwill appear from the following detailed description of a species thereofand from the accompanying drawing.

In the drawing, FIG. 1 is an elevation of an electric incandescent lampprovided with a base end structure comprising my invention, a part ofthe base structure at one end of the lamp being shown partly broken awayto more clearly illustrate the invention.

FIG. 2 is a longitudinal section of the lamp comprising my invention onthe line 2-2 of FIG. l, and

FIG. 3 is a fragmentary perspective view of one end of the electricincandescent lamp shown in FIGS. 1 and 2.

Referring to the drawing, the invention. is there illustrated as appliedto an electric incandescent lamp of the double-ended type such asdisclosed in the aforementioned co-pending Ayres et al. applicationSerial No. 848,282 and comprising a sealed elongated glass bulb orenvelope 1 preferably of tubular shape and closed oif at its oppositeends. The envelope 1 is provided at its opposite ends with protrudingflat glass stem press portions 2 through which lead-in conductors orwires 3 are sealed so as to protrude endwise therefrom. Interiorily ofthe envelope 1, the lead-in wires 3 are connected to the opposite endsof an electrical energy translation element or filament 4 of a suitablerefractory metal such as tungsten, and preferably in the form of astraight coil of tungsten wire supported by the lead-in wires 3 in aposition extending more or less axially of the tubular envelope 1. Theenvelope 1 contains a suitable inert gas filling such as argon, forexample, at a pressure below atmospheric.

As shown in FIG. 2, the protruding flat stern press portions 2 at theopposite ends of the envelope 1 are disposed in the same axial plane ofthe lamp envelope and they are formed with shallow indentations ornotches 5 in one or both of their flat side faces 6 to provide sharplateral shoulders 7 on the stem press portions facing inwardly of theenvelope. As shown, the said indentations 5 are located more or lesscentrally across the width of the respective stem press portions 2. Thelead-in wires 3 project outwardly from the outer ends 8 of the sternpress portions 2 at points likewise located more or less centrallyacross the width of the stem press portions, and their outwardlyprojecting portions 9 are bent back around the said ends 8 of the sternpress portions to extend back alongside one of the flat sides 6 thereofand across the respective indentation 5 therein.

Mounted on and enclosing each stem press portion 2 is a hollow baseshell member or metal cap 10 having fiat sides 11 corresponding to theflat sides 6 of the stem press portion. The base shell or metal end capmembers 10 are made of thin sheet metal of suitable spring character,such as brass for instance, and they are provided with inwardlydeflected spring tongues or detents 12 in one or both of their flatsides 11 which are adapted to snap into the respective indentations 5,when the base members 10 are slip-fitted over the ends of the stem pressportions and pushed the full distance back thereonto. The free ends ofthe spring tongues :12 are thereby caught behind the lateral shoulders 7on the stern press portions 2 so as to lock the base shell membersecurely in place on the stem press portion against endwise removaltherefrom. The spring tongues or detents 12 are preferably formed as anintegral part of the base shell members '10 by simply pressing orpunching the spring tongues out of the fiat sides 1-1 of the base shellmembers.

During the assembly of each base shell or end cap member 19 onto thestem press portion 2, the spring action of the spring tongues 12, insnapping into the indentations 5, acts to deform the portions 9 of thelead-in wires, overlying the indentations, downwardly thereinto andagainst the bottom wall thereof so as to resiliently clamp the lead-inwire portions 9 firmly against the bottom of 3, the respectiveindentation to thereby form a good electrical connection with thelead-in conductor.

It will be apparent from the above description, therefore, that I haveprovided a simple and easily assembled base end construction for anelectric lamp or other similar electrical device wherein the assemblyand fastening of the base shell member onto the lamp envelope, and theformation of the electrical connection of the base shell member tothelead-in wire of the lamp or other device, is automatically effected by asimple push-on movement of the base shell member onto the end of thelamp envelope, without the need of any additional manufacturingoperations. Also, because of the use of metal end caps 10 such as shownat the opposite ends of the lamp, it is possible to utilize the lampwith sockets of the type in which the electrical connection to the lampis made to its opposite end extremities.

What I claim as new and desire to secure by Letters Patent ofthe UnitedStatesis:

1. An electrical device comprising a sealed glass envelope provided'witha protruding flat stem press portion having a shallow indentation in oneof its flat sides forming a sharp lateral shoulder on the stem pressfacing inwardly of the envelope, a lead-in conductor sealed into saidstem press portion and protruding endwise therefrom, said conductorbeing bent around the outer end of said stem press portion to extendalongside the said one ofits flat sides and across the said indentationtherein, and a hollow metal base member slip-fitted over the end of saidstem press and provided with an inward spring tongue caught within thesaid indentation behind the said lateral shoulder thereof to lock thebase securely in place on the stem pressagainst endwise removaltherefrom, said spring tongue resiliently clamping the said lead inconductor firmly against the bottom of said indentation to form agoodelectrical connection with said conductor.

2. An electrical device comprising a sealed glass envelope provided witha protruding fiat stem press portion having shallow indentations in itsopposite flat sides forming sharp lateral shoulders on the stem pressfacing inwardly of the envelope, a lead-in conductor sealed into saidstern press portion and protruding endwise there-from, said conductorbeing bent around the end of said stern press portion to extendalongsideone of its flat sides and across the said indentation therein, and ahollow metal base member slip-fitted over the end of said stern pressand provided with-inward spring tongues caught within the said.indentations behind the said lateral shoulders thereof to lock the basesecurely in place on the stem press against endwise removal therefrom,one of said spring tongues resiliently clamping the said lead-inconductor firmly against the bottom of the respective indentation toform a good electrical connection with said conductor.

3. An electrical device comprising a sealed glass en- 5 said stem pressportion and protruding endwise therefrom,

said conductor being bent around the outer end of said stem pressportion to extend alongside the said one of its flat sides and acrossthe said indentation therein, and a hollow metal base shell mounted onand enclosing the said stem press and having flat side portionscorresponding to and disposed closely alongside the said fiat sides ofthe stem press, one of the said flat side portions of said base shellbeing provided with an inward spring tongue portion pressed outtherefrom and having its free end snap-caught within the saidindentation behind the said lateral shoulder thereof to lock the baseshell securely in place on the stern press against endwise removaltherefrom, said spring tongue resiliently clampingthe said lead-inconductor firmly against the bottom of the said indentation to form agood electrical connection with said conductor.

4. An electric lamp comprising a sealed tubular glass envelope providedat its opposite ends with protruding fiat stempress portions disposed ina common plane, each of said fiat stern press portions having shallowindentations in its opposite flat sides forming sharp lateral shoulderson the respective stern press portions facing inwardly of the envelope,lead-in wires sealed through respective ones of said stern pressportions and extending into said envelope, a filament disposed withinsaid envelope and connected at its opposite ends to said lead-in wires,said lead-in wires protruding endwise from said stem press portions andbeing bent around the outer ends thereof to extend alongside one oftheir flat sides and across the respective indentation therein, andhollow metal base shells mounted on and enclosing the respective stempress portions and having flat side portions corresponding to anddisposed closely alongside the fiat sides of the stern press portions,each of the flat side portions of said base shells being provided withan inward spring tongue portion pressed out therefrom and having itsfree end snap-caught within the respective indentation in the sternpress behind the said lateral shoulder thereof to lock the base shellsecurely in place on the stern press against endwise removalitherefrom,one of the said spring tongues of each base shell resiliently clampingthe respective lead-in wire firmly against'the bottom of'the indentationin the respective stem press portion to thereby form a good electricalconnection with said lead-in wire.

References Cited in the file of this patent UNITED STATES PATENTSBohlman Oct. 2, 1923 Hodge Mar. 29, 1955

4. AN ELECTRIC LAMP COMPRISING A SEALED TUBULAR GLASS ENVELOPE PROVIDEDAT ITS OPPOSITE ENDS WITH PROTRUDING FLAT STEM PRESS PORTIONS DISPOSEDIN A COMMON PLANE, EACH OF SAID FLAT STEM PRESS PORTIONS HAVING SHALLOWINDENTATIONS IN ITS OPPOSITE FLAT SIDES FORMING SHARP LATERAL SHOULDERSON THE RESPECTIVE STEM PRESS PORTIONS FACING INWARDLY OF THE ENVELOPE,LEAD-IN WIRES SEALED THROUGH RESPECTIVE ONES OF SAID STEM PRESS PORTIONSAND EXTENDING INTO SAID ENVELOPE, A FILAMENT DISPOSED WITHIN SAIDENVELOPE AND CONNECTED AT ITS OPPOSITE ENDS TO SAID LEAD-IN WIRES, SAIDLEAD-IN WIRES PROTRUDING ENDWISE FROM SAID STEM PRESS PORTIONS AND BEINGBENT AROUND THE OUTER ENDS THEREOF TO EXTEND ALONGSIDE ONE OF THEIR FLATSIDES AND ACROSS THE RESPECTIVE INDENTATION THEREIN, AND HOLLOW METALBASE SHELLS MOUNTED ON AND ENCLOSING THE RESPECTIVE STEM PRESS PORTIONSAND HAVING FLAT SIDE PORTIONS CORRESPONDING TO AND DISPOSED CLOSELYALONGSIDE THE FLAT SIDES OF THE STEM PRESS PORTIONS, EACH OF THE FLATSIDE PORTIONS OF SAID BASE SHELLS BEING PROVIDED WITH AN INWARD SPRINGTONGUE PORTION PRESSED OUT THEREFROM AND HAVING ITS FREE END SNAP-CAUGHTWITHIN THE RESPECTIVE INDENTATION IN THE STEM PRESS BEHIND THE SAIDLATERAL SHOULDER THEREOF TO LOCK THE BASE SHELL SECURELY IN PLACE ON THESTEM PRESS AGAINST ENDWISE REMOVAL THEREFROM, ONE OF THE SAID SPRINGTONGUES OF EACH BASE SHELL RESILIENTLY CLAMPING THE RESPECTIVE LEAD-INWIRE FIRMLY AGAISNT THE BOTTOM OF THE INDENTATION IN THE RESPECTIVE STEMPRESS PORTION TO THEREBY FORM A GOOD ELECTRICAL CONNECTION WITH SAIDLEAD-IN WIRE.